Questions about Conceptual Design 1 by

Why identifiers and not primary keys?

2024-02-04 11:20:26 UTC

In our conceptual or data models you include identifiers not primary keys. I thought databases had primary keys?

Seminar Slide (Main Task)

2024-02-17 21:46:42 UTC

I'm curious about one thing when you gave us the answer of the main task. You said that in the ER diagram, there is no relationship between SALES_ASSISTANT and CAR. However, in the question, it mentions about "Customer details(forename, surname and contact phone number), and the cars they are interested in, are recorded by just one sales assistant." Can you explain more about this point?

Redundancy task question

2024-02-19 14:03:31 UTC

In the redundancy example, how should we think about which entity should keep the TYPE attribute. In the example we kept it on EMAIL_TYPE, however wouldn't keeping it on EMAIL also be okay? Does the context matter or does it not matter which one we pick?